[PATCH v3 2/3] Documentation: dt: add bindings for TI Wakeup M3 IPC device

From: Dave Gerlach
Date: Tue Sep 22 2015 - 20:17:01 EST


Add the device tree bindings document for the TI Wakeup M3 IPC
device on AM33xx and AM43xx SoCs. These devices are used by the
TI wkup_m3_ipc driver, and contain the registers upon which the
IPC protocol to communicate with the Wakeup M3 processor is
implemented.

Signed-off-by: Dave Gerlach <d-gerlach@xxxxxx>
Signed-off-by: Suman Anna <s-anna@xxxxxx>
---
v2->v3: Unchanged.

.../devicetree/bindings/soc/ti/wkup_m3_ipc.txt | 57 ++++++++++++++++++++++
1 file changed, 57 insertions(+)
create mode 100644 Documentation/devicetree/bindings/soc/ti/wkup_m3_ipc.txt

diff --git a/Documentation/devicetree/bindings/soc/ti/wkup_m3_ipc.txt b/Documentation/devicetree/bindings/soc/ti/wkup_m3_ipc.txt
new file mode 100644
index 0000000..4015504
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/ti/wkup_m3_ipc.txt
@@ -0,0 +1,57 @@
+Wakeup M3 IPC Driver
+=====================
+
+The TI AM33xx and AM43xx family of devices use a small Cortex M3 co-processor
+(commonly referred to as Wakeup M3 or CM3) to help with various low power tasks
+that cannot be controlled from the MPU, like suspend/resume and certain deep
+C-states for CPU Idle. Once the wkup_m3_ipc driver uses the wkup_m3_rproc driver
+to boot the wkup_m3, it handles communication with the CM3 using IPC registers
+present in the SoC's control module and a mailbox. The wkup_m3_ipc exposes an
+API to allow the SoC PM code to execute specific PM tasks.
+
+Wkup M3 Device Node:
+====================
+A wkup_m3_ipc device node is used to represent the IPC registers within an
+SoC.
+
+Required properties:
+--------------------
+- compatible: Should be,
+ "ti,am3352-wkup-m3-ipc" for AM33xx SoCs
+ "ti,am4372-wkup-m3-ipc" for AM43xx SoCs
+- reg: Contains the IPC register address space to communicate
+ with the Wakeup M3 processor
+- interrupts: Contains the interrupt information for the wkup_m3
+ interrupt that signals the MPU.
+- ti,rproc: phandle to the wkup_m3 rproc node so the IPC driver
+ can boot it.
+- mboxes: phandles used by IPC framework to get correct mbox
+ channel for communication. Must point to appropriate
+ mbox_wkupm3 child node.
+
+Example:
+--------
+/* AM33xx */
+ l4_wkup: l4_wkup@44c00000 {
+ ...
+
+ scm: scm@210000 {
+ compatible = "ti,am3-scm", "simple-bus";
+ reg = <0x210000 0x2000>;
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0 0x210000 0x2000>;
+
+ ...
+
+ wkup_m3_ipc: wkup_m3_ipc@1324 {
+ compatible = "ti,am3352-wkup-m3-ipc";
+ reg = <0x1324 0x24>;
+ interrupts = <78>;
+ ti,rproc = <&wkup_m3>;
+ mboxes = <&mailbox &mbox_wkupm3>;
+ };
+
+ ...
+ };
+ };
--
2.4.6

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